Camshafts are needed for actuating the inlet and outlet valves in internal combustion engines, wherein due to the complexity of modern camshafts, assembly and installation thereof becomes increasingly difficult.
From DE 103 31 089 A1, a generic cylinder head cover for an internal combustion engine having at least one camshaft is known, which camshaft protrudes through at least one bearing bridge along a bearing channel for the camshaft in the cylinder head cover, wherein said bearing bridge has an opening or bore that completely encloses the camshaft.
From DE 10 2007 014 544 A1, an internal combustion engine having at least one camshaft is known, which camshaft, for forming an axial bearing, has at least one stop element that interacts with a bearing frame of the axial bearing for axial mounting. The stop element is formed by a cam of the camshaft, and the bearing frame also provides a free space for the cam shape of the cam. Through this, axial mounting via a cam can be achieved.
From DE 10 2009 031 455 A1, a further internal combustion engine is known, which has a camshaft system with a first camshaft for controlling gas exchange valves of the internal combustion engine. A gearwheel is arranged rotationally fixed on said camshaft. In order to be able to implement axial mounting of the camshaft in a manner as simple as possible, a housing part of the internal combustion engine has an internal housing recess in which the gearwheel is circumferentially guided at least in certain sections in such a manner that the gearwheel, at least with end face regions of its two opposing gearwheel end faces, interacts in each case with a side wall region of in each case one side wall of the recess. The gearwheel thus has two functions, namely, on the one hand, as a drive element and, on the other, as an axial bearing for the camshaft.
From DE 10 2009 049 218 A1, a camshaft of an internal combustion engine having at least one one-piece pressure disc is known, which pressure disc is arranged between a drive element fixedly joined with the camshaft and a functional element that likewise is fixedly joined with the camshaft and, moreover, is captively fixed therebetween.
All above-described solutions for axially mounting a camshaft in an internal combustion engine have in common that the complete camshaft is placed into a split bearing arrangement such as, for example, a bearing block or a split cylinder head. This cannot be done in the case of a camshaft assembled in a cylinder head cover or a bearing frame, so that in this case, the axial bearing usually is implemented by a ball bearing (cf. DE 103 31 089 A1). However, such a ball bearing requires significant radial installation space in the cylinder head cover or the bearing frame, which is contrary to the advantage of a cylinder head cover, namely to provide a light and compact design. Also, conventional axial mounting by means of slide bearings, for example, by attaching two flanged cams at two sliding surfaces in the housing often proves to be problematic since there is only little space available in the cylinder head for such cams. However, holding the cam during assembly proves to be a particular problem because normally only one of the two cams can be held in a properly supported manner on a plane surface in the insertion direction of the shaft.